diff options
| -rw-r--r-- | drivers/spi/spi.c | 15 | ||||
| -rw-r--r-- | include/linux/spi/spi.h | 15 |
2 files changed, 30 insertions, 0 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index fd1372fe0505..bf4027b54a19 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -2995,6 +2995,21 @@ int spi_setup(struct spi_device *spi) } EXPORT_SYMBOL_GPL(spi_setup); +/** + * spi_set_cs_timing - configure CS setup, hold, and inactive delays + * @spi: the device that requires specific CS timing configuration + * @setup: CS setup time in terms of clock count + * @hold: CS hold time in terms of clock count + * @inactive_dly: CS inactive delay between transfers in terms of clock count + */ +void spi_set_cs_timing(struct spi_device *spi, u8 setup, u8 hold, + u8 inactive_dly) +{ + if (spi->controller->set_cs_timing) + spi->controller->set_cs_timing(spi, setup, hold, inactive_dly); +} +EXPORT_SYMBOL_GPL(spi_set_cs_timing); + static int __spi_validate(struct spi_device *spi, struct spi_message *message) { struct spi_controller *ctlr = spi->controller; diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index a0975cf76cf6..589f9dc9ac2b 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -330,6 +330,9 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv) * must fail if an unrecognized or unsupported mode is requested. * It's always safe to call this unless transfers are pending on * the device whose settings are being modified. + * @set_cs_timing: optional hook for SPI devices to request SPI master + * controller for configuring specific CS setup time, hold time and inactive + * delay interms of clock counts * @transfer: adds a message to the controller's transfer queue. * @cleanup: frees controller-specific state * @can_dma: determine whether this controller supports DMA @@ -363,6 +366,7 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv) * @unprepare_transfer_hardware: there are currently no more messages on the * queue so the subsystem notifies the driver that it may relax the * hardware by issuing this call + * * @set_cs: set the logic level of the chip select line. May be called * from interrupt context. * @prepare_message: set up the controller to transfer a single message, @@ -488,6 +492,17 @@ struct spi_controller { */ int (*setup)(struct spi_device *spi); + /* + * set_cs_timing() method is for SPI controllers that supports + * configuring CS timing. + * + * This hook allows SPI client drivers to request SPI controllers + * to configure specific CS timing through spi_set_cs_timing() after + * spi_setup(). + */ + void (*set_cs_timing)(struct spi_device *spi, u8 setup_clk_cycles, + u8 hold_clk_cycles, u8 inactive_clk_cycles); + /* bidirectional bulk transfers * * + The transfer() method may not sleep; its main role is |